Method of separating optically active glutamic acid without racemization



Patent ed a. 16, 1934 UNITED STATES PATENT OFFICE 1.916.997 METHOD OF SEPABATHVG 0 PT! CALLY ACTIVE GLUT IMIZATION Sciao Kanao, Azabn Kn,

to Kabushiki Kaisha C ACID WITHOUT RAGE- Tokyo, Japan, assignor Suzuki Shoten, Tokyo,

Japan, incorporation oi Japan No Drawing. Application April 664,840. In Japan April 12,1932 3 Claims. (Cl. 260-118) great seasoning power by preventing the racemization of glutamic acid.

If'alkali hydroxide or alkali carbonate is used in separating glutamic acidfrom glutamic acid hydrochloride or other mineral acid salt ofglu- 'tamic acid, it is. inevitable that glutamic acid should be partly racemized. This'tendency may be somewhat lessened by the employment of ammonia, but even then the racemization to some extent is unavoidable. According to thisinvengo tion, by using a glycocoll alkyl derivative vsuch as betaine or sarcosine as a neutralizer, the optical rotatory glutamic acid, which is inevitably racemized with ordinary alkaline matter, is separated without reducing its rotatory power in the least and glutamic acid is crystallized as a big crystal, so that it can be separated from the mother liquor and washed and refined with ease.

Laevo-rotatory glutamic acid a far weakerv taste than the dextro-rotatory acid. Therefore, the racemization reduces the value of dextrorotatory'glutamic acid considerably when utilized as a seasoning, so it is a matter of great significance to separate dextro-rotatory glutamic acid without racemization. Emmple-'I;l83.5 grams of dextro-rotatory glutamic acid hydrochloride was dissolved in A 0.6 litre of water and then the solution was mixed with 117' grams of betaino by a stirrer, the crystal of betaine vanished immediately and the o I,

' is added to crystal of dextro-rotatory glutamic acid was formed. After cooling, it was filtered and then washed with water. 7 Thus, it was possible to obtain 140 grams of the product having the melt-" ing point -201.5-202 C. and the specific rotatory power (solution of hydrochloric acid). The mother liquorvconsisting of betaine hydrochloride, betaine may be recovered by the proper treatment.

Example IL-II 11.7 grams of powdered betaine' solutionoi sulphuric acid salt of dextro-rotatory'glutamic-acid consisting of 14.7 grams of dextro-rotatory glutamic acid and 66 c. c. of 1.5 normal solution of sulphuric acid, it is dissolved to a clear solution and the crystal oi dextro-rotatory glutamic acid will be produced pretty soon. .When the crystal is collected by 76 filtration and washed with water, substantially the same result as above is obtained.

I claim: I

1. A method of recovering optically active dextro-rotatory glutamic acid from its mineral acid 80 salts without racemizatio comprising neutralizingthe combined mineral acid of said salts with an alkyl derivative of glycocoll.

2. A method 01 recovering optically active dextro-rotatory glutamic acid from its mineral acid salts without racemization, comprising neutraliz- 1 ing the combined mineral acid of said salts with betaine.

3. A method of recovering optically active dextro-rotatory glutamic acid from its mineral acid salts without racemization, comprising neutralizing the combined mineral acid oi saidsalts with sarcosine; I

SEIZO KANAO. 

